The present invention relates to an operator assembly for opening and closing and, more particularly, to an electrical window operator.
Operators are known for moving a window between closed and open positions, for example, a window having a stationary main frame mounted in a roof of a house or other building, especially a sloped roof, and a sash hinged to the main frame at the top of the sash for pivoting toward and away from the main frame. Such operators are typically mounted on a bottom member of the main frame and connected to a bottom member of the sash for pushing the sash away from the main frame and drawing the sash into engagement with the main frame. When the window operator is actuated to move the window in an opening direction it must overcome a component of the weight of the window, especially when the window is mounted in a roof.
In manually operated window openers which may typically be of the kind in which one or a pair of scissors-connected arms are pivotally connected in one end with the sash and in the other end with a manual drive mechanism arranged at the main frame this problem may typically be overcome by providing counterbalancing spring devices to counteract the weight component of the window and, thereby, reduce the force to be applied to the operator for opening the window. Window operators of this kind are disclosed in U.S. Pat. Nos. 5,097,629 to Guhl et al and 2,698,173 to Rydell.
Another way of solving this weight problem is to employ electrical operation of a window opener by connecting the drive mechanism provided at the main frame with an electrical drive unit such as disclosed in U.S. Pat. No. 4,553,656.